The present invention relates to a pedal crank bearing assembly, more particularly, to a pedal crank bearing assembly for bicycles, which has first and second races having a threaded end defined in an end periphery thereof threadedly engaged to a tube and a stop is fixed on the tube and engaged to a serrated face of the second race to prevent it from loosening.
A conventional pedal crank bearing assembly is shown in FIG. 1, which includes an axle 10, a tube 20, two caps 31 32 and a housing 30. The axle 10 is rotatably engaged within the tube 20 which has thread portions defined in outer periphery of both ends thereof for engagement with a housing 30 and the caps 31 and 32 are mounted on both ends of the housing for keeping dust from entering. Two bearings 41, 42 are disposed between the axle 10 and the tube 20 to provide a better rotational efficiency. In order to maintain a position of the bearing 42, a race 43, a washer 44 and a nut 45 are threadedly mounted on a thread section 12 of the axle 10. However, as a bicycle often encounters rough and uneven terrain, especially for a mountain bike, the engagement of the housing 30 and the tube 20 tends to loosen and that increases damage occurring between the threading relationship of the housing 30 and the tube 20, and further causes the axle 10 to have a poor operating feature. Furthermore, the bearing assembly could be shocked severely, and in such a situation the nut 45 has a high possibility of loosening from the thread section 12 and that causes an instability of the bearing 42. Another shortcoming is that the procedure to adjust the bearing assembly is complex, whereby a user must disengage the cap 32 first and then he or she has to use a socket tool to unscrew the nut 45.
The present invention intends to provide an improved pedal crank bearing assembly to mitigate and/or obviate the above-mentioned problems.